The sweet almond (prunus amygdalus) belongs to a family of fruit trees which includes the apricot, the peach and the plum. Dietary habits relating to the fruits of these trees differ markedly. As a consequence, the flesh part of the apricot, of the peach and of the plum is the portion which is consumed—either as a fresh, dried, or preserved product. The plum is often dried to a condition called a prune. Prune juice is the water extract of the dried prune. In every culture, the inside of the apricot, peach or plum is discarded. Only the outer flesh (the mesocarp) is recovered and consumed in some way.
The almond has had a remarkably different history. In some cultures, particularly in the Mediterranean, the flesh is consumed while it is a fresh product, and is greatly enjoyed. However, in most of the world, and especially in the United States, the important crop is the inside nut. The flesh part is only rarely consumed as such, and not as a major crop. Instead, the almond fruit is permitted to remain on the tree for a very extended time well into senescence. The flesh part (mesocarp) dries to a moisture content of between about 5%–29% by weight, preferably about 10% while still on the tree.
During this time while still on the tree, the almond mesocarp has entered a period of biological senescence. After collection from the tree and separation from the nut meat, it is regarded as a low-value product, generally called the “almond hull”. This is in contrast with other fruits, which are harvested before senescence has set in and have their own sets of taste and content. In their situations, the nuts are discarded and the mesocarp is eaten while in what can be regarded as a youthful phase. However, for almonds, the nut is the crop, and the mesocarp is used as a fuel to be burned, or is fed to cattle as a feed supplement. It is an under-appreciated fact that almond hulls contain useful fiber and various phytochemicals useful as dietary supplements.
It is known that almond hulls contain inositol, sugars, and various other compounds including lignin, but the inventor herein is unaware of any prior effort (certainly not a commercially successful effort) not only to obtain useful dietary fiber, but also to prepare augmented almond hull dietary fiber, relying principally on the inherent contents of the almond hull itself for its ultimate compositions, and on benign processes for doing it.
There has been found a relationship between human populations which consume low fiber diets and a higher incidence of gastrointestinal (GI) cancers in those populations. The scientific and medical literature on this subject is now huge, and growing. Considerably more is now known about the chemical composition of “dietary fiber” and its real and possible roles in prevention of several diseases, primarily afflicting the ageing, including cancer, cardiovascular disease, and diabetes, in addition to a few dozen diseases which center on the GI tract, such as Crohn's disease, ulcerative colitis, and colorectal cancer. In view of this increased knowledge of the basic chemistry of dietary fiber, and its putative medical benefits, the United States Food and Drug Administration is currently considering an update of the scientific definition of dietary fiber (frequently hereinafter referred to as “DF”).
One of the first definitions of DF, still quite serviceable is: Dietary Fiber (DF) consists of the remnants of edible plant cells, polysaccharides, lignin, and associated substances resistant to hydrolysis and digestion by the alimentary (i.e GI tract) enzymes of humans. The reference to human enzymes is significant, because since this definition was proposed, it is now appreciated that the normal microbial population (bacteria, yeasts, and fungi) of the human GI tract, play important roles in maintenance of health. These microbes have the enzyme capability to digest selected fractions of DF, to the benefit of their hosts.
The new FDA definition perhaps to be announced in 2002, will be important, as it will directly impact nutritional labeling of foods and supplements, and regulatory matters relating to allowable health claims. DF's derived from cereals have been shown to beneficially affect laxation, by virtue of both their insoluble polysaccharide fraction, and soluble polysaccharide fraction, via different mechanisms for the two different fractions. Further, specific sub-fractions of DF polysaccharides have been shown to be responsible for enhanced laxation. It appears that fruit and vegetable DF, may have greater prophylactic activity against GI cancers, than do cereals DF. This activity, however, may also be due at least in part, to the antioxidant actions of fruit and vegetable polyphenolic compounds, such as flavonoids, lignans, anthyocyanidins.
It is an object of this invention, to make use of a unique augmented DF, achieved by proper processing of currently under-utilized fruit, which is actually the waste product of the commercial farming and harvesting of a different component of this fruit. Further, the DF which can be recovered from this fruit, can also be augmented with other phytochemical components of the fruit, in novel ways, so as to increase the beneficial DF and prebiotic actives of this augmented DF. A prebiotic is a food or supplement which contributes to a healthy intestinal microbial population.
The almond has a unique mixture of polysaccharides (e.g. cellulose, hemicelluloses, etc.) sugars, and polyphenolics (e.g. flavonoids, anthocyanidins, lignans, and lignins), and other organics and minerals content. It differs from other harvested fruits by having undergone a significantly different biochemical anabolic and catabolic process while still on the tree. The inventor herein has learned that, after comminution of the dried fruit (the almond hull) to a fine or coarse powder, the dried fruit can be rehydrated with water, allowing separation of water soluble sugars, and other low molecular weight organics, from a remaining, predominantly higher molecular weight polysaccharide plus polyphenolic solids residue. Lower molecular weight sugars, and other organics (including flavonoids, terpenes, anthocyanidins, lignans), can also be separated from the fruit via, for example, supercritical carbon dioxide extraction, or via water plus organic solvent mixtures leaving a similar remaining higher molecular weight residue. Extraction techniques using only water is preferred for both food safety and process economics advantages.